Positionally independent mercury contact arrangement



Sept. 19, 1967 w. BOSCH 3,342,965

POSITIONALLY INDEPENDENT MERCURY CONTACT ARRANGEMENT Filed Dec. 14, 1966 INVENTOR M e/We/ 5050/? ATTYS.

United States Patent Aktiengesellschaft, Berlin and Munich, Germany, a corporation of Germany Filed Dec. 14, 1966, Ser. No. 601,665 Claims priority, application Germany, Dec. 22, 1965,

01 104 5 Claims. Cl: 200-452 The invention relates to a positionally independent contact arrangement with a mercury drop located in a spherical hollow space, deformable by an electromechanical final control element. It is a known fact that contact arrangements with mercury operate fundamentally free from chattering. Its use, however, is possible only under certain conditions as often an independence of position and high switching speeds are required, which characteristics cannot be attained in view of the relatively large amount of mercury necessary in known liquid contacts. It has already been proposed to avoid these advantages by the utilization as switching liquid only a small quantity of mercury in the form of a mercury drop. In this case, as a result of the large surface tension of the mercury, the drop, in opposition to the force of gravity, always endeavors to reassume its original spherical shape after deformation in any of its possible operating positions.

Proceeding from this knowledge, it is the purpose of the invention to create a positionally independent contact arrangement, constructed in simple manner, in which arrangement a mercury drop is utilized, located in a spherical hollow space and deformable by an electromechanical final control element. In this case, above all the ability of an inexpensive production is required.

According to the invention, this is obtained by the feature that a hollow space located within a body of insulating material, serving for the reception of an approximately spherical mercury drop, is sealed by a platelike connecting electrode, with a second further connecting electrode being disposed approximately at the level of the maximum transverse cross section of the mercury drop, which electrode is provided with a circular opening encircling the mercury drop with the maintenance of a certain minimum distance. A pressure liquid, located in a preferably conical-shaped pressure space, is effective over a connection channel to produce an operating deformation of the mercury drop, the pressure space being sealed on the operating side of the contact arrangement by a membrane. This construction not only enables a simple production, but the contact arrangement permits, in addition to the independence of position, as a result of the hydraulic power actuation, a high switching speed.

A development of the invention provides, for the separation of the pressure liquid from the mercury drop, a flexible intermediate layer, preferably an insulating sheet or foil, such intermediate layer being embedded in the wall of the spherical hollow space adjacent the connection channel. Preferably radially extending slots are provided in edges of the circular opening of the connecting electrode encircling the mercury drop for the compensation of excessive pressure resulting from an over actuation of the electromechanical final control element.

Preferably an electromagnetic system acting upon the membrane serves as final control element for the movement of the pressure liquid and therewith for the deformation of the mercury. However, instead of an electromagnet system any other electromechanical driving method can be employed, such as are customary in switches operating in relay-like manner.

Further details of the invention will be obvious from the following description of a constructional example thereof, and the drawings, in which:

FIG. 1 is a vertical section through a contact arrangement according to the invention; and

FIG. 2 is a sectional view taken approximately on the line A-A of FIG. 1.

Referring to FIG. 1 in which the main constructional parts of the contact arrangement are illustrated, a body 3 of insulating material is provided which serves as a carrier for a drop of mercury, the body being formed with a spherically-shaped hollow space 311 for the reception of the mercury drop. The bottom of such hollow space is closed by a plate-like connecting electrode 7 so that the mercury is continuously in physical connection with such electrode. A further connecting electrode 5 is located approximately at the height of the maximum transverse cross section of the mercury drop, such electrode being provided with a circular recess 5a which encircles the mercury drop -8, with the maintenance of a certain minimum distance.

From the spherical hollow space 3a a connection channel 3b extends to a cone-shaped pressure space 30, such pressure space being filled with a pressure liquid 1. A membrane 2 seals the pressure liquid with respect to the exterior. If the membrane 2 is moved in the direction of the arrow by a final control element, for example by an electromagnet system, a deformation of the mercury drop 8 occurs and portions of the mercury flow into the opening 5a of the connection electrode 5 whereby an electrical connection is effected between this electrode and the electrode 7, closing the spherical hollow space 3a. The electrical lead connection points to these electrodes are designated a and b. Since the opening 5a in the connection electrode 5 is still enlarged by the addition of slots 5b, the mercury can flow into such radially extending slots in the event of an excessive travel of the final control element. If the final control element is again returned into the rest position and therewith the membrane 2 likewise resumes its rest position, the mercury drop 8, because of the high surface tension, likewise resumes its original spherical shape, whereby the contact connection between the connecting electrodes 5 and 7 is broken. In order to avoid an intermixing of or chemical reactions between the mercury and the pressure liquid, they may be physically separated by an intermediate flexible layer 4. In this case, such intermediate layer, preferably constructed in the form of an insulating sheet or foil, is embedded in the wall of the spherical hollow space 3a, facing the connection channel 3b.

Since the proportions of such a contact arrangement can be kept extremely small because of its simple construction, multiple contacts with extremely small total volume also may be readily produced, in which case the pressure liquid can simultaneously act upon several physically separated mercury drops.

Changes may be made within the scope and spirit of the appended claims which define what is believed to be new and desired to have protected by Letters Patent.

I claim:

1.' A positionally independent contact arrangement utilizing a mercury drop located in a spherical hollow space and deformable by an electromechanical final control element, comprising a body of an insulating material having an approximately spherical hollow space therein, a drop of mercury disposed in said space, a plate-like connecting electrode disposed to form a closure for said space, a second connecting electrode, disposed approximately at the level of the maximum transverse cross section of the mercury drop and having an opening therein the edges of which encircle the mercury drop but spaced a certain minimum distance therefrom, said body having a pressure space for an actuating pressure liquid disposed therein, said body further having a connection channel therein operatively connecting said pressure space with 3 said hollow mercury containing space, whereby pressure on said liquid is operative to eflect an operating deformation of the mercury drop, and operative connection thereby of the respective electrodes, and a membrane forming a vflexible closure of said pressure spacewith respect to the exterior, and through which the liquid pressure in said pressure space may. be controlled.

2. A contact arrangement according to claim 1, comprising in further combination, a flexible intermediate layer disposed in said hollow mercury containing space adjacent to said connection channel and operatively separating said mercury drop from said pressure liquid.

3. A contact arrangement according to claim 1, wherein said opening in the second connecting electrode is circular in shape and provided with radially extending slots open- 15 ing on such circular opening.

4. A contact arrangement according to claim '1, wherein said membrane is acted upon by an electromagnet system which serves as the final control element for the movement of the pressure liquid and therewith the deformation of the mercury drop.

5. A contact arrangement according to claim l, wherein said pressure space is comically-shaped and diverges from said connection channel.

References Cited UNITED STATES PATENTS 3,184,693 5/1965 Lanctot 200 152x ROBERT K. SCHAEFER, Primary Examiner. H. HOHAUSER, Assistant Examiner. 

1. A POSITIONALLY INDEPENDENT CONTACT ARRANGEMENT UTILIZING A MERCURY DROP LOCATED IN A SPHERICAL HOLLOW SPACE AND DEFORMABLE BY ELECTROMECHANICAL FINAL CONTROL ELEMENT, COMPRISING A BODY OF AN INSULATING MATERIAL HAVING AN APPROXIMATELY SPHERICAL HOLLOW SPACE THEREIN, A DROP OF MERCURY DISPOSED IN SAID SPACE, A PLATE-LIKE CONNECTING ELECTRODE DISPOSED TO FORM A CLOSURE FOR SAID SPACE, A SECOND CONNECTING ELECTRODE, DISPOSED APPROXIMATELY AT THE LEVEL OF THE MAXIMUM TRANSVERSE CROSS SECTION OF THE MERCURY DROP AND HAVING AN OPENING THEREIN THE EDGES OF WHICH ENCIRCLE THE MERCURY DROP BUT SPACED A CERTAIN MINIMUM DISTANCE THEREFROM, SAID BODY HAVING A PRESSURE SPACE FOR AN ACTUATING PRESSURE LIQUID DISPOSED THEREIN, SAID BODY FURTHER HAVING A CONNECTING CHANNEL THEREIN OPERATIVELY CONNECTING SAID PRESSURE SPACE WITH SAID HOLLOW MERCURY CONTAINING SPACE, WHEREBY PRESSURE ON SAID LIQUID IS OPERATIVE TO EFFECT AN OPERATING DEFORMATION OF THE MERCURY DROP, AND OPERATIVE CONNECTION THEREBY OF THE RESPECTIVE ELECTRODES, AND A MEMBRANE FORMING A FLEXIBLE CLOSURE OF SAID PRESSURE SPACE WITH RESPECT TO THE EXTERIOR, AND THROUGH WHICH THE LIQUID PRESSURE IN SAID PRESSURE SPACE MAY BE CONTROLLED. 